21 October 2021
News Ticker

E131 – Patent Blue V

Number: E131

Name: Patent Blue V

Other names: Cl 42051, Food Blue 5, Sulphan Blue, Acid Blue 3, L-Blau 3, C-Blau 20, Patentblau, Sky Blue

Function: Colour

Description: blue colour

Origin: Synthetic dye


  • it isn’t widely used  but in Europe it can be found in Scotch eggs, certain jelly sweets, blue Curaçao, certain jello varieties (though not in actual Jell-O brand products), among others
  • in medicine, E131 is used in lymphangiography and sentinel node biopsy as a dye to color lymph vessels.
  • it is also used in dental disclosing tablets as a stain to show dental plaque on teeth.

Daily intake: up to 15 mg/kg body weight

Side effects:

  • rare allergic reactions have been described, due to coupling of the colour to (body) proteins
  • it is a histamine liberator and may intensify symptoms of asthma


  • can be consumed by all religious groups, vegans and vegetarians
  • important advantage is the very deep color it produces even at low concentration, a disadvantage is that it fades fairly quickly when exposed to light
  • very soluble in water